Currently, straw bale construction is not only exploding in popularity with the niche of natural builders but is also quickly gaining acceptance to the mainstream construction market. In 2002 alone, the construction market used approximately 1,000,000 traditional straw bales for building construction and this projected use is expected to grow every year. In part, this is due to the realization of benefits attainable from the use of straw bales. For example, such benefits include overcoming limitations in traditional building resources (e.g., wood, cement and otherwise), allowing individuals and businesses to partake in one or more of environmentally sensitive design decisions, reduction in construction cost of structures, improved insulation and sound abatement values of walls and buildings and the disposal of unusable straw stalks.
The agricultural industry is faced with annually disposing of tons of unusable straw, particularly rice straw originating from the oryza sativa plant. After cultivation, remaining rice straw stalks remain unused and require disposal. However, burning of this plant, to make room for the following season's crop, is either impractical or is unlawful. Additionally, rice straw stalks lack substantive nutritional values, providing little value as a fertilizer or other foodstuff. Further, in some instances, it is possible that stalks may contain diseases or insects, which especially in combination with its slow decay rate, make it impractical to mix the remaining stalk with planting soil.
However, particularly because of its composition and resistance to decay, rice straw stalk lends itself to other applications, such as in construction materials. For example, a relatively high concentration of silica, in some types of straw stalks, provides advantages such as fire resistance and reduction of insect infestation. Certain other naturally occurring substances are present in the stalks.
However, as this realization of beneficial use and demand has evolved, the industry is still struggling in providing suitable straw bales as discussed in more detail below.
One problem the building industry has encountered is the lack of a standardized straw bale for construction. This is particularly problematic when a large quantity of uniform blocks are required such as when attempting to design and build medium to large sized structures or when designing a plurality of buildings such as in a residential subdivision or otherwise. This is due, in part, to the lack of availability of suppliers offering straw bales having, at a minimum, a common size and weight. As previously mentioned, in 2002 one million straw bales were used for building construction and the majority, if not all, of the straw bales were provided directly by independent farmers. As such, contractors have typically been required to adjust their building practices based upon the fluctuating size and quality of the bales produced by a particular farmer's equipment and baling practices.
For example, some suppliers (e.g. farmers) offer straw bales having a general size comprising a length of 48 inches, a width of 18 inches and a height of 24 inches, which has a tendency to be very cumbersome in size and weight. In practice, however, it has been observed that the achievement of consistency and uniformity among the products of different suppliers has been difficult to achieve
While the fledgling industry could help toward improving this problem, with stringent certifications or standards, such regulation is believed difficult to implement, largely because of the vast range of available processing techniques and variables, as well as raw material characteristics, and the resulting unpredictability from the combination of the foregoing.
Accordingly, not only would it be attractive to provide a construction material effectively comprising recycled straw stalks that have little other practical use, but it would be especially desirable to provide such a material that will yield consistent and uniform characteristics, and optionally further provide for multifunctional use, such as a mounting surface, a surface subject to coating or a combination thereof.
Various aspects of the present invention meet at least one or a combination of the above needs by providing precisely engineered straw bales and more particularly a straw block that will conform to standard building practices and distribution systems and is engineered to be used for load bearing structures, sound abatement walls, combinations thereof or otherwise. The present invention also provides advantages over a traditional straw bales by providing at least one or a combination of two or more of: 1) uniformed sized straw blocks having tolerances of about ⅛ inches or less and includes 90 degree cut angles, 2) a straw block that is internationally certified by International Codification Council (ICC), 3) a straw block having a unit weight of only about 40 to 55 lbs as oppose to tradition bales which commonly weigh 80 lbs. or more, 4) a straw block suitable for vertical stacking in order to create load-bearing wall system, and 5) a straw block having a rigid flat, interior and/or exterior face which can support staples nails screws and other types of fasteners, and particular offering a face that has a sufficient texture for permitting surface coating for visibly pleasing surface finish characteristics, thus being especially adaptable for easy lath and stucco applications.
Other benefits and advantages of the present invention will be further ascertained herein, including but not limited to providing an environmentally friendly approach for use of post harvest rice straw stalks.